1. Field of Invention
The present invention relates to the field of marine seismic surveying. More specifically, the invention relates to marine seismic sources and methods of improving seismic images obtained using same.
2. Related Art
Marine seismic exploration investigates and maps the structure and character of subsurface geological formations underlying a body of water. For large survey areas, seismic vessels tow one or more marine seismic sources and multiple seismic streamer cables through the water. The seismic sources typically comprise compressed air guns (or other types of source) for generating acoustic pulses in the water. Some of the energy from these pulses propagates downwardly into the geological formations and is reflected upwardly from the interfaces between subsurface geological formations. This reflected energy, along with ghost signals from other surfaces, are sensed with hydrophones attached to the seismic streamers, and data representing such energy is recorded and processed to provide information about the underlying geological features. Ghosting may be reduced by controlling position and timing of the sources, and/or by controlling position of streamers. The streamers may be positioned using steerable birds, deflectors, steerable buoys, and the like.
Previous attempts have not provided optimal de-ghosting of marine seismic images. While these techniques are improvements in the art, further improvement is desired.